The aim of this project is to study the reflex mechanisms and the neural pathways involved in pulmonary reflexes. It will link the previous research efforts of the principal investigator on J-receptor reflexes with reflexes from other pulmonary afferents. One of the aims of the project is to study these reflexes in the newborn and the different ages of development of the reflexes - an aspect that has escaped attention so far. The J-receptor reflexes will be studied using physiological stimuli -- pulmonary congestion and pulmonary edema. This will be the first attempt made to study the manner in which these reflexes operate under physiological conditions. There will be considerable emphasis placed on the motor inhibition from pulmonary receptors and recording from central neurons will be done using conventional neurophysiological and histological techniques. The principal investigator is interested in vagal afferent and central respiratory interactions and will be involved in assessing the relative role played by different pulmonary receptors in various pulmonary reflexes. In essence this project addresses the question: How do vagal afferents exert their influence on respiratory mechanisms and motor systems and where is this information processed?